Optical semiconductor devices (light emitting devices) of the SMD (surface mounted device) type and having the structure shown in FIG. 3 have often been used in recent years in place of a lead type of optical semiconductor device in an effort to reduce the size and thickness of the optical semiconductor device. With a surface mounted type of optical semiconductor device, usually an optical semiconductor element (LED, etc.) 400 is mounted via a die-bonding material 406 on the bottom face of a recessed part of an optical semiconductor element mounting package in which positive and negative lead electrodes 404 are integrated with a resin molding 403 having a recessed part that serves as the region where the optical semiconductor element will be mounted. And then, the optical semiconductor element 400 and the lead electrodes 404 are electrically connected with a bonding wire 401, after which the recessed part is packed with a transparent sealing resin 402 that includes a fluorescent material 405, and the optical semiconductor element 400 is sealed to complete the manufacture of the optical semiconductor device. The above-mentioned optical semiconductor element mounting package is usually manufactured by placing lead electrodes in a mold, injecting a molten thermosetting resin composition into the closed mold, and returning the resin composition to room temperature to cure it and integrate the components. Japanese Laid-Open Patent Applications 2002-280616, 2004-055632, and 2004-342782 disclose an SMD-type LED apparatus that makes use of an optical semiconductor element mounting package in which positive and negative lead electrodes and a resin molding having a recessed part are integrated.